1. Field of the Invention
The present invention relates to a supported catalyst for a fuel cell, a method of manufacturing the same, and a fuel cell and, more particularly, to a supported catalyst for a fuel cell which includes a conductive support and a platinum alloy supported thereby, a method of manufacturing the same, and a fuel cell using the same.
2. Description of the Related Art
Some platinum alloys have catalytic activity higher than that of platinum. To improve the performance of a fuel cell, therefore, it is effective to use supported catalysts each including a conductive support and a platinum alloy supported thereby. However, a fuel cell using such supported catalysts deteriorates with time more easily than a fuel cell using supported catalysts each including a conductive support and platinum supported thereby.
To solve this problem, it is being attempted to suppress the deterioration of a fuel cell with time by improving the durability of the supported catalysts.
For example, Jpn. Pat. Appln. KOKAI Publication No. 6-176766 describes a method by which platinum, nickel, and cobalt are supported by conductive supports, and thereafter, platinum is alloyed with nickel and cobalt by heating at a temperature equal to or higher than 600° C. and lower than 800° C. to produce a regular structure in the platinum-nickel-cobalt ternary alloy. Also, Jpn. Pat. Appln. KOKAI Publication No. 2001-52718 describes a method which includes causing carbon supports to support platinum so as to produce supported platinum catalysts, adding a base metal to the supported platinum catalysts to produce supported alloy catalysts, partially removing the base metal from the supported alloy catalysts by elution, bringing the supported alloy catalysts into contact with carbon monoxide, and annealing the supported alloy catalysts in an inert atmosphere. Note that in addition to these references, Jpn. Pat. Appln. KOKAI Publication Nos. 9-161811, 2003-142112, and 2003-45442 are references related to the present invention.
These methods can suppress the deterioration of a fuel cell with time to a certain degree. However, the life characteristics achieved by these methods are not necessarily satisfactory.